Objective: To evaluate the outcome of pregnancies complicated by first-trimester intrauterine hematoma.
Methods: An analysis was performed on 248 cases. The pregnancy outcome was correlated with hematoma volume, gestational age (weeks), and maternal age (years).
Results: One hundred eighty-two cases were eligible for the study. Clinical complications occurred in 38.5% of the cases (adverse outcome group). Spontaneous abortion (14.3%), fetal growth restriction (7.7%), and preterm delivery (6.6%) were the most frequent clinical conditions observed. Considering the hematoma variables in adverse and favorable outcome groups, we found a significant difference only for gestational age at diagnosis. The median gestational age was significantly lower (P < .02) in the adverse outcome group (7.27, I and III quartiles 6.22-8.78) than in the favorable outcome cases (8.62, I and III quartiles 6.70-9.98). Among clinical conditions, the median gestational age was significantly lower (P = .02) in pregnancies complicated by spontaneous abortion (6.60, I and III quartiles 5.95-8.36) than in cases not ending in a miscarriage (8.50, I and III quartiles 6.70-9.91). The overall risk of adverse outcome was 2.4 times higher when the hematoma was diagnosed before 9 weeks (odds ratio 2.37, 95% confidence interval 1.20-4.70). In particular, intrauterine hematoma observed before 9 weeks significantly increases the risk of spontaneous abortion (odds ratio 14.79, 95% confidence interval 1.95-112.09)
Conclusion: Intrauterine hematoma can affect the outcome of pregnancy. The risk of spontaneous abortion is related to gestational age and is significantly increased if diagnosed before 9 weeks.
Level of evidence: III.